Study of highly boosted forced heat transfer for applications connected with reactor equipment in the sphere of pre- and supercritical parameters

1. Study of the heat transfer, critical heat loads and flow friction in the the terms of exterior problem. Study of critical heat flows in the rod bundle with the cylindrical fuel element simulators, year 1980

Experimental study of the heat emission in a boiling process in the rod bundles was conducted in the Kyiv Order of Lenin Basic Research Laboratory of the Polytechnic Institute according to Coordination plan of scientific-research works on “Thermo-physics” problematic AS USSR, code 1.0.4.6. (6).

Report contains:

Description of the test bench, work site, instrumentation plan, methodic of experimentation, processing of research data and accuracy assessment of measured and design values;

Results of the experiment in research of the heat emission crisis in the rod bundle with cylindrical imitators of heat producing elements in the diapason of operating conditions.

2. Experimental study of the distribution of thermo-hydraulic characteristics of the steam-water flow along the section of heated rod assembly, year 1979.

Report contains results of the experiments in the research of mass flux and steam content distribution between the specific cells of assembly and definition of pressure drop on the heated length of the bundle in the diapason of operating conditions. Comparison of the experimental results obtained in 1987 with the results of the calculations in the program “bundle-2” and its analysis.

3. Study of local heat transfer in the cells of rod assemblies. Development of methods for heat transfer intensification in the measuring channels and channels cooled by single-phase coolant, year 1985.

A comprehensive study of thermal-hydraulic parameters (distribution of the mass flow rate and enthalpy of the cross section, hydraulic resistance, heat-transfer crisis) in a seven-rod assembly with a round displacer and unheated central rod has been conducted. The report provides an overview of literature, description of the test bench and the site, research methods and experimental results obtained in the diapason of certain parameters.

4. Theoretic and experimental study of local thermal-hydraulic parameters of rod assemblies of rotors’ active zones with single-and two-phase coolant, including accounting methods and methods of heat transfer intensification".

The results of experimental studies of the costs distribution and relative enthalpies of water and steam mixture between the elementary cells of the bundle, as well as the conditions of crisis heat transfer while boiling in rod assembly with distance grids-intensifiers are represented. The experiments were conducted on seven-rod bundle with a central unheated rod, set in a round displacer in a range of operational parameters specific to the RBMK-1500. Data on critical heat loads and the distribution of the flow parameters the along the section of bundle with grating-intensifiers were obtained for the first time. It can be used for processing of cellular heat hydraulic analysis methods for the evaporation channels of nuclear reactors.

5. Development of the computer calculation approximate equations of the specific volume, density, and their mean integral value in the diapason of enthalpies from 100 to 1100 kcal / kg and pressures from 100 to 600 kgf/cm2.

This paper, which is an extension of previous NTUU “KPI” works , with the help of orthonormal Chebyshev polynomials tabulated values ​​of specific volumes and densities depending on enthalpy at constant pressure and approximated by a single formula in a wide diapasons of enthalpies (100-1100 kcal / kg) and pressures ( 100-600 kgf/cm2).

Based on these formulas there are expressions for the first derivatives of specific volume and density by enthalpy and mean integral values of the specific volume and density which are recommended for hydraulic calculations of steam generators on a computer.